Magnetic latches are used in a variety of applications ranging from industrial electromagnetic coupling devices to cupboard and refrigerator latches. These invariably make use of the comparatively strong holding force in the direction of the magnetic flux lines. None of these devices incorporate a combined adjustable and safety release magnetic locking mechanism.
The present invention arose from the need for a quick release mechanism for windsurfer/sailing board body support harnesses. All available body harnesses make use of a hook affixed to a spreader bar. To use the harness, the board sailer hooks on to a looped line hanging from the wishbone of the windsurfer board. The pull of the sail is then transferred to the torso of the sailor who leans backward to achieve a lever arm balance between the vertical lift of the sail and the downward pull of gravity. To free himself from the looped line (and hence the wishbone and sail), the board sailor must pull forward on the wishbone with his arms. This releases the tension on the line and allows it to fall free of the hook attached to the spreader bar. Problems arise when the board sailor accidentally hooks onto the line or is pulled suddenly to leeward by a gust of wind, a wave induced lurch of the board or some other abrupt motion. The board sailor is unable to unhook by releasing the line tension and frequently becomes entangled in the line as he topples into the water.